Knitted fabric having open areas

Abstract

A fabric having open areas is knitted from a plurality of body yarns interspersed at intervals with locking yarns having a lower melting temperature by casting off selected loops in selected body yarns, causing the cast-off loops to unravel toward but not past the respective locking yarn, and heating the fabric to cause the locking yarns to fuse to the touching body yarns, thereby preventing the cast-off loops from unraveling past the respective locking yarn.

That which is claimed is: 
     
       1. A method of preparing a double knit fabric having a plurality of relatively open areas, which comprises: (I) forming a double knit fabric by (a) knitting at least one body course employing at least one first yarn;   (b) then knitting, in immediate succession to said at least one body course, at least one first locking course employing at least one second yarn, said second yarn being formed of a thermoplastic material having a lower melting point than said first yarn; and   (c) then in immediate succession to said at least one first locking course, knitting a first plurality of consecutive body courses employing a plurality of first yarns while causing, in each of a plurality of areas in said first plurality of consecutive body courses, at least one stitch to be cast off;     (II) stressing the thus knitted fabric to cause the thus cast-off stitches to unravel to a point near to but not past said at least one first locking course employing at least one second yarn;   (III) heating the thus stressed fabric to a temperature above the melting point of said at least one second yarn and below the melting point of said first yarns to cause said at least one second yarn to fuse to the first yarns touching said at least one second yarn; and   (IV) cooling the thus heated fabric to a temperature below the melting point of said at least one second yarn to thereby prevent the cast-off stitches from unraveling through said at least one first locking course employing at least one second yarn.   
     
     
       2. A method in accordance with claim 1 wherein the step of forming said fabric further comprises (d) knitting, in immediate succession to said first plurality of consecutive body courses, at least one second locking course employing at least one second yarn of said thermoplastic material; and   (e) then knitting in immediate succession to said at least one second locking course, a second plurality of consecutive body courses employing a plurality of first yarns while causing, in each of a plurality of areas in said second plurality of consecutive body courses, at least one stitch to be cast off; and wherein the step of stressing the thus knitted fabric causes the respective cast-off stitches to unravel to a point near to but not past the at least one second yarn of the next preceding locking course.     
     
     
       3. A method in accordance with claim 2 wherein said thermoplastic material is a polymer of propylene. 
     
     
       4. A method in accordance with claim 3 wherein each of said first yarns is a nylon yarn. 
     
     
       5. A method in accordance with claim 3 wherein each of said first yarn is a polyester yarn. 
     
     
       6. A method in accordance with claim 1 wherein the cast-off stitches are made by selected cylinder needles and by selected dial needles. 
     
     
       7. A method in accordance with claim 6 wherein said selected cylinder needles and said selected dial needles are inactivated for several courses immediately following the production of the respective cast-off stitches to thereby produce segments of single knit fabric and are then reactivated to resume production of double knit fabric. 
     
     
       8. A method in accordance with claim 7 wherein said cast-off stitches occur at predetermined intervals. 
     
     
       9. A method in accordance with claim 8 wherein said cast-off stitches have a longer stitch length than the average stitch length for the fabric. 
     
     
       10. A method in accordance with claim 9 wherein the knit stitches in said second yarns corresponding to the respective cast-off stitches have a longer length than the average stitch length for the fabric. 
     
     
       11. A method in accordance with claim 1 wherein each said second yarn is a spun yarn. 
     
     
       12. A method in accordance with claim 1 wherein each said second yarn is a textured yarn. 
     
     
       13. A double knit fabric having a plurality of relatively open areas, which comprises at least one body course containing at least one first yarn;   in immediate succession to said at least one body course, at least one first locking course containing at least one second yarn, each said second yarn being formed of a thermoplastic material having a lower melting point than said first yarn; and   in immediate succession to said at least one first locking course, a first plurality of consecutive body courses containing a plurality of first yarns, in each of a plurality of areas in said first plurality of consecutive body courses at least one stitch having been cast off and unraveled toward but not past said at least one first locking course;   said at least one second yarn being fused to the touching first yarns to prevent said cast-off stitches from unraveling past said at least one second yarn.   
     
     
       14. A fabric in accordance with claim 13 further comprising in immediate succession to said first plurality of consecutive body courses, at least one second locking course containing at least one second yarn of said thermoplastic material; and   in immediate succession to said at least one second locking course, a second plurality of consecutive body courses containing a plurality of first yarns, in each of a plurality of areas in said second plurality of consecutive body courses at least one stitch having been cast off and unraveled toward but not past said at least one second locking course;   said at least one second yarn of said at least one second locking course being fused to the touching first yarns to prevent said cast-off stitches of said second plurality of consecutive body courses from unraveling past said at least one second yarn of said at least one second locking course.   
     
     
       15. A fabric in accordance with claim 14 wherein said thermoplastic material is a polymer of propylene. 
     
     
       16. A fabric in accordance with claim 15 wherein each of said first yarns is a nylon yarn. 
     
     
       17. A fabric in accordance with claim 15 wherein each of said first yarns is a polyester yarn. 
     
     
       18. A fabric in accordance with claim 13 wherein each said second yarn is a spun yarn. 
     
     
       19. A fabric in accordance with claim 13 wherein each said second yarn is a textured yarn. 
     
     
       20. A fabric in accordance with claim 13 wherein said cast-off stitches have a longer stitch length than the average stitch length for the fabric. 
     
     
       21. A fabric in accordance with claim 20 wherein the stitches in said second yarns corresponding to the respective cast-off stitches have a longer length than the average stitch length for the fabric. 
     
     
       22. A fabric in accordance with claim 21 wherein each of said first yarns is a polyester yarn and each of said second yarns is a polypropylene yarn. 
     
     
       23. A method in accordance with claim 2 wherein said second yarn is a single yarn.